When uncontrolled wildfires moved from the foothills above Los Angeles into the densely populated urban areas below in January 2025, evacuation ensued and a thick layer of toxic smoke spread across the region. Air quality plummeted. Local hospitals braced for a surge,.听听

Research led by the 天美影视传媒 and Kaiser Permanente Southern California sheds new light on how the Los Angeles fires affected people鈥檚 health, and how people navigated the health care system during an emergency. In the rapid study, published , researchers analyzed the health records of 3.7 million Kaiser Permanente members of all ages living in the region. They found that health care visits did rise above normal levels, especially virtual services.听听

In the week after the fires ignited, Kaiser Permanente members made 42% more virtual visits for respiratory symptoms than expected. Those living near a burn zone or within Los Angeles County also made 44% and 40% more virtual cardiovascular visits, respectively, than expected.听

In-person outpatient visits for respiratory symptoms also increased substantially. Members who lived near a burn zone or within Los Angeles County made 27% and 31% more virtual cardiovascular visits, respectively, than expected.听

Extrapolating to all insured residents of the county, the researchers estimated an excess of 15,792 cardiovascular virtual visits, 18,489 respiratory virtual visits and 27,903 respiratory outpatient visits in the first week of the fires.听

The results suggest that people may rely more heavily on virtual health care during climate-related emergencies, and that providers should better prioritize virtual and telehealth services as they prepare for future crises.听

鈥淲e saw over 6,241 excess cardiorespiratory virtual visits in the week following the fire ignition. This represents a substantial increase in care,鈥� said, a UW associate professor of environmental and occupational health sciences and of epidemiology who led the research. 鈥淲hile the fires clearly impacted health, virtual care likely enhanced the ability of providers to meet the health care needs of people experiencing an ongoing climate disaster.鈥澨�

In collaboration with Kaiser Permanente Southern California, an integrated health care system with millions of members across the region, researchers analyzed health records of people who were highly or moderately exposed to wildfires. They defined high exposure as living within about 12 miles (20 kilometers) of a burn zone, and moderate exposure as living within Los Angeles County but farther than 12 miles during the time of the fires.听听

Researchers looked back three years to estimate how many health care visits to expect in the weeks following Jan. 7 鈥� the first day of the fires 鈥� under typical conditions. They then estimated how many people sought care in the first week of the fires, when smoke levels were highest, evacuations took place, and Los Angeles County public schools were closed.

In addition to the spike in cardiovascular and respiratory visits, researchers found a sharp increase in the number of visits for injuries and neuropsychiatric symptoms. On Jan. 7, outpatient injury visits were 18% higher than expected among highly exposed members, and virtual injury visits were 26% and 18% higher than expected among highly and moderately exposed groups, respectively. Among those same groups, outpatient neuropsychiatric visits rose 31% and 28% above expectations, respectively.

While both groups made significantly more visits than expected, proximity to the fires mattered. When researchers zoomed in on respiratory-related virtual visits, they found that minimally exposed members made 31% more visits, moderately exposed members made 36% more, and those living in highly exposed areas made 42% more.听听

鈥淲hile healthcare systems often plan to increase the number of hospital beds available or clinic staffing during an emergency, this work highlights the importance of considering virtual care capacity,鈥� said, a UW doctoral student of epidemiology and co-author on the study. 鈥淭his may be particularly true for climate disasters like wildfires, during which people are advised to stay indoors or when people must evacuate 鈥� motivating them to seek care online if at all possible. As climate disasters increase in frequency and intensity, it is essential that health care systems know how to prepare for a sudden and dramatic surge in health care utilization.鈥澨�

Other authors on this study are , and of Kaiser Permanente Southern California; of the University of California, Berkeley; of Kaiser Permanente Hawaii; and of Columbia University; and of the Scripps Institution of Oceanography at UC San Diego; and of the Scripps Institution and the University of Rennes in France.

This research was funded by the National Institute on Aging and the National Institute for Environmental Health Sciences.听

For more information or to reach the research team, contact Alden Woods at acwoods@uw.edu.

About . Birth before 37 weeks can lead to a cascade of health risks, both immediate and long-term, making prevention a vital tool for improving public health over generations.听

In recent years, researchers have identified a potential link between wildfire smoke 鈥� one of the fastest-growing sources of air pollution in the United States 鈥� and preterm birth, but no study has been big or broad enough to draw definitive conclusions. A new study led by the 天美影视传媒 makes an important contribution, analyzing data from more than 20,000 births to find that pregnant people who are exposed to wildfire smoke are more likely to give birth prematurely.

鈥淧reventing preterm birth really pays off with lasting benefits for future health,鈥� said lead author , a UW postdoctoral researcher in environmental and occupational health sciences. 鈥淚t鈥檚 also something of a mystery. We don鈥檛 always understand why babies are born preterm, but we know that air pollution contributes to preterm births, and it makes sense that wildfire smoke would as well. This study underscores that wildfire smoke is inseparable from maternal and infant health.鈥�

In the study, ,听researchers used data from the , a federal research project focused on how a wide range of environmental factors affect children鈥檚 health. The sample included 20,034 births from 2006-2020 across the contiguous United States.

Researchers estimated participants鈥� average daily exposure to fine particulate matter, or PM2.5, generated by wildfire smoke, and the total number of days they were exposed to any amount of smoke. They estimated the intensity of smoke exposure by how frequently participants were exposed to wildfire PM2.5 levels above certain thresholds.

They found that pregnant people exposed to more intense wildfire smoke were more likely to give birth prematurely. In mid-pregnancy, exposure to any smoke was associated with an elevated risk of preterm birth, with that risk peaking around the 21st week of gestation. In late pregnancy, elevated risk was most closely associated with exposure to high concentrations of wildfire PM2.5, above 10 micrograms per cubic meter.

鈥淭he second trimester is a period of pregnancy with the richest and most intense growth of the placenta, which itself is such an important part of fetal health, growth and development,鈥� said co-author , a UW professor of environmental and occupational health sciences and of pediatrics in the UW School of Medicine. 鈥淪o it may be that the wildfire smoke particles are really interfering with placental health. Some of them are so tiny that after inhalation they can actually get into the bloodstream and get delivered directly into the placenta or fetus.鈥澨�

The link was strongest and most precise in the Western U.S., where people were exposed to the highest concentrations of wildfire PM2.5 and the greatest number of high-intensity smoke days. Here, the odds of preterm birth increased with each additional microgram per cubic meter of average wildfire PM2.5.

It鈥檚 possible those results were more precise simply because the West experiences more wildfire smoke on average, making the exposure model perform better, Sherris said. But there may be other factors behind the regional differences.听

The composition of wildfire smoke is different across the country. In the West, smoke tends to come from fires nearby, while in places like the Midwest, smoke has typically drifted in from faraway fires. and reacts with sunlight and airborne chemicals, which could have affected the results. Researchers also noted that external factors like co-occurring heat or housing quality may have effects that aren鈥檛 fully understood.听

Researchers hope that future studies will examine the exact mechanisms by which wildfire smoke might trigger preterm birth. But in the meantime, Sherris said, evidence for a link is now strong enough to take action.听

鈥淭here are a couple avenues for change,鈥� Sherris said. 鈥淔irst, people already get a lot of public health messaging and information throughout pregnancy, so there鈥檚 an opportunity to work with clinicians to provide tools for pregnant people to protect themselves during smoke events. Public health agencies鈥� messaging about wildfire smoke could also be tailored to pregnant people and highlight them as a vulnerable group.鈥�

Co-authors include , doctoral student of environmental and occupational health sciences at the UW; , clinical associate professor of environmental and occupational health sciences at the UW; , professor of biostatistics at the UW; , associate professor of environmental and occupational health sciences and of epidemiology at the UW; , postdoctoral fellow of epidemiology at the UW; and , assistant professor of environmental and occupational health sciences at the UW. A full list of co-authors is included with the paper.

This research was funded by the Environmental influences on Child Health Outcomes (ECHO) program at the National Institutes of Health under multiple awards. A full list of ECHO funding awards is included with the paper.听

For more information or to contact the researchers, email Alden Woods at acwoods@uw.edu.

An associated video has been removed from this post.

As Baby Boomers hit retirement, about is now over the age of 65. The number of Americans living with dementia is 鈥� but the proportion of older Americans who develop dementia has actually decreased. The exact reason why is uncertain, but various lifestyle and environmental factors can of cognitive decline.听听

One recently discovered risk is air pollution. exposure to a type of air pollution called fine particulate matter, or PM2.5, with an increased risk of developing dementia, and researchers suspect that some sources of PM2.5 may pose a greater risk than others.听

New research led by the 天美影视传媒 found that wildfire smoke is especially hazardous. An analysis of the health care records of 1.2 million Southern California residents found that higher long-term smoke exposure was associated with a significant increase in the odds that a person would be diagnosed with dementia.听听听

The researchers at the Alzheimer鈥檚 Association International Conference in July and

鈥淭here have been studies that have found total PM2.5 is related to people developing dementia, but no one had looked specifically at wildfire PM2.5,鈥� said lead author , a UW associate professor of environmental & occupational health sciences. 鈥淲ildfire smoke is a different animal, in that it鈥檚 much spikier. There are many days where there鈥檚 no wildfire smoke, and there are some days where exposure is really, really extreme.鈥�听

Researchers analyzed the health records of 1.2 million members aged 60 and older of Kaiser Permanente Southern California between 2008 and 2019, all of whom were free from dementia at the start of the study period. They estimated each person鈥檚 long-term exposure to both wildfire and non-wildfire PM2.5 as a three-year rolling average, and then identified people who received a dementia diagnosis.听

Researchers found that for every 1 microgram per cubic meter (碌g/m3) increase in three-year average wildfire PM2.5 concentration, the odds of a dementia diagnosis increased by 18%. Exposure to non-wildfire PM2.5 also increased a person鈥檚 risk of dementia, but to a much lesser degree.听听

鈥淥ne microgram per meter cubed might sound fairly small, but we have to think about how people are exposed to wildfire smoke,鈥� Casey said. 鈥淢ost days they aren鈥檛 exposed at all, so this might represent a few days of exposure at a concentration of something like 300 碌g/m3, where the AQI is over 200 in someone鈥檚 community. When you think about it, it鈥檚 actually a few really severe wildfire smoke days that might translate into increased risk.鈥�听

That risk further increased among racialized people and those living in high-poverty census tracts, following long-term trends in which vulnerable populations often experience disproportionate effects of environmental hazards. The authors suggested that disparities might be related to lower-quality housing, which can increase the amount of smoke that enters people鈥檚 homes, or lower-income families鈥� inability to afford air filtration systems.听听

The study period does not include the summers of 2020 and 2021, which produced the most recorded in California. The climate crisis has the frequency and severity of wildfires across the American West, introducing 鈥渟moke season鈥� in many West Coast regions The influx of smoke has at air quality improvements made over the last century.听

“The main culprit here is climate change,鈥� Casey said. 鈥淚t’s a global problem. While individuals can protect themselves with air filters and masks, we need a global solution to climate change. It’s going to have to be many-pronged听鈥� many people have to be involved to solve this highly complex problem.”听

Co-authors on this study are Holly Elser of the University of Pennsylvania; Timothy Frankland of the Kaiser Permanente Hawaii Center for Integrated Health Research; Chen Chen and Tarik Benmarhnia of the Scripps Institution of Oceanography at UC San Diego; Sara Tartof and Gina Lee of Kaiser Permanente Southern California; Elizabeth Rose Mayeda of UCLA; Dr. Alexander Northrop of Columbia University; and Jacqueline Torres of UC San Francisco. This research was funded by the National Institute on Aging and the National Institute for Environmental Health Sciences.听

鈥淔or me it was an inconvenience, but for some people it could be life-threatening,鈥� said , now an assistant professor in the 天美影视传媒鈥檚 Department of Environmental and Occupational Health Sciences. 鈥淚f you had an uncle that had an electric heart pump, basically, his heart wouldn鈥檛 work without power. You could use a backup battery for eight hours, but after that, if you don鈥檛 have access to electricity, you have to go to the emergency room. This is a really dangerous situation.鈥�

Years later, Casey has answers. April 29 in the journal Nature Communications analyzed three years of power outages across the U.S., finding that Americans already bearing the brunt of climate change and health inequities are clustered in four regions 鈥� Louisiana, Arkansas, central Alabama and northern Michigan 鈥� and that they are most at risk of impact by a lengthy blackout.

The findings could help shape the future of local energy infrastructure, especially as climate change intensifies and the American power grid continues to age. Last year鈥檚 Inflation Reduction Act included billions of dollars to revamp energy systems, and Casey hopes federal agencies will consult the newly published findings to target energy upgrades.听

The study is the first county-level analysis of power outages, which the federal government reports only at the state level. That poses a problem for researchers: a federally reported outage in Washington state could occur in Seattle, Spokane, or somewhere in between, making it difficult to understand specifically which population is affected.听

Casey and her team found that between 2018 and 2020, more than 231,000 power outages lasting more than an hour occurred nationwide. Of those, 17,484 stretched at least eight hours 鈥�听a duration widely viewed as medically relevant.

Most counties that experienced an electrical outage had at least one event lasting more than eight hours. These counties were most concentrated in the South, Northeast and Appalachia.

Next, researchers looked at how power outages overlapped with severe weather. They wanted to know which weather events are most likely to cause an outage, and which parts of the U.S. are most often hit with a blackout-causing storm.

They found that heavy precipitation in a given area makes a power outage five times more likely. Tropical cyclones, storms with high winds that originate over tropical oceans, make a power outage 14 times more likely. And a tropical cyclone with heavy precipitation on a hot day 鈥� like the hurricanes that each fall hit the Gulf Coast? They make power outages 52 times more likely.

鈥淲e look at weather reports and decide whether or not to bring an umbrella or stay home,鈥� Casey said. 鈥淏ut thinking about being prepared for an outage when one of these events is rolling through is a new element to consider.鈥�

Then came questions of equity. Incorporating a combination of socioeconomic and medical factors, Casey鈥檚 team identified communities that would likely be especially vulnerable during a long power outage. Using that data, the researchers were able to identify communities that experienced both high social vulnerability and frequent power outages.听听

A map of those counties shows a bright cluster in Louisiana and Arkansas, with more clusters in central Alabama and northern Michigan. In those places especially, the country鈥檚 inevitable change in energy infrastructure provides the greatest opportunity to improve public health.

鈥淎ny time we can identify another factor that we can intervene on to get closer to health equity, it鈥檚 exciting,鈥� Casey said. 鈥淚 think we鈥檙e going to see tremendous change, especially in the way our energy systems are set up, in the next couple decades. It鈥檚 this huge opportunity to get equity into every conversation and talk about what we鈥檙e going to do to make two decades from now look different from where we are.鈥�听

This study began while Casey was a professor in Columbia University鈥檚 Mailman School of Public Health. Other authors are Vivian Do (first author), Heather McBrien, Nina Flores, Alexander Northrop and Jeffrey Schlegelmilch at Columbia University and Mathew Kiang at Stanford University. The research was funded by the National Institute on Aging and the National Institute of Environmental Health Sciences. 听

For more information, contact Casey at jacasey@uw.edu.听

Heat is a quiet killer. Unlike most natural disasters, which can leave visible damage across an entire region, a heat wave鈥檚 effects on human health can be difficult to track. So after record high temperatures struck the Pacific Northwest in the summer of 2021, included only people killed directly by heat exposure.听听

A new study led by , a professor in the 天美影视传媒鈥檚 Department of Environmental and Occupational Health Sciences shows those estimates don鈥檛 capture the true toll. the American Journal of Public Health, the study found that over the three weeks beginning June 25, 2021, dangerously high temperatures contributed to an additional 159 injury deaths across Washington state.听听

To reach that figure, Casey and a team of researchers first calculated how many people might have been expected to die from injuries over that same period had the heat wave not happened. They then compared that estimate with official death records. 听

The result听includes deaths that the heat wave contributed to indirectly, including drownings, transportation accidents, violence and self-harm. Prior studies have shown a strong correlation between temperature spikes and deaths from injury.听听

鈥淥fficial death tolls may miss deaths not immediately and obviously tied to high temperatures, but those previously counted may represent just the tip of the iceberg, to use a poor analogy for a heat wave,鈥� said Casey, who is the lead author and conducted this research while on the faculty听at Columbia University.听

Caused by a ridge of high pressure that trapped hot air over the region, the 2021 heat wave brought unprecedented temperatures to the Pacific Northwest. It likely won鈥檛 be the last such event. Climate models project that with 2 degrees Celsius of warming, similar heat waves would occur every five to 10 years, and would likely reach even higher temperatures.听听

That combination poses a serious threat to public health, making it even more important to understand and plan for future heat waves鈥� widespread impact. The researchers recommended several actions public health officials could take to prevent injuries indirectly caused by heat waves, including promoting safe swimming to prevent drownings and offering mental health services to stem violence and self-harm.听听

鈥淧ublic health officials should allocate a portion of their budget to these extreme but increasingly common events,鈥� Casey said. 鈥淐ommunities require additional support for things like cooling centers 鈥� especially in places like the Pacific Northwest, where air conditioning is not common.鈥�听

Other authors include Robbie Parks of Columbia University; Tim Bruckner of the University of California, Irvine; Alison Gemmill of Johns Hopkins University; and Ralph Catalano of the University of California, Berkeley. This research was funded in part by the National Institute of Environmental Health Sciences.听

For more information, contact Casey at jacasey@uw.edu.听听